Aesthetix Atlas power amplifier

In Greek mythology, Atlas was the Titan who supported the heavensalthough he's more commonly shown supporting Earth itself. (Funny thing, that: the globe he was always shown supporting actually did once represent the cosmos, but at some point became the Earth.) According to Hygenus, Atlas was the son of Aether, the personification of the sky and heaven, and Gaia, the personification of the Earth. Atlas was brother to Prometheus (foresight), Epithemius (hindsight), and Menoetius (a warrior whose insolence got him smitten by a lightning bolt from Zeus, resulting in a name synonymous with "ruined strength").

In other words, Atlas was a heavy hitter; if you name something after him, it had better be spectacular. Jim White, chief designer and head honcho at Aesthetix Audio, was surely aware of all this when he had the chutzpah to name his 200Wpc hybrid power amplifier after the brawny Titan. The question is, was he justified in that confidence?

Mapping a Titan
The Atlas ($8000) is a hefty beast at 70 lbs, and is wrapped in an aluminum enclosure that surrounds the circuits and heatsinks in a cage-in-cage construction. The Atlas's two transformers and three chokes are housed under a stainless-steel cover to prevent magnetic fields from interfering with the audio circuitry. The B+ tube power-supply is discretely regulated with each channel's driver stage supply separately regulated. The 1400VA transformer feeds a choke, which in turn feeds the high-current output section..

The voltage gain stage employs one 6SN7 tube per channel. The current-amplifying output stage, designed in conjunction with Ayre Acoustics' Charles Hansen, uses 16 bipolar output devices per channel and there is no global negative feedback. Each channel's output devices are connected by massive copper bus bars, which radically reduces impedance, according to White, though it is fair to note that the Atlas has a relatively high specified output impedance of 0.25 ohm. The Atlas's construction and circuit layout appear to be superlative.

An unusual feature of the Atlas is its 6dB/octave high-pass crossover, which can be set to 16 different values between 40 and 200Hz. It's handy if you use a subwoofer (or a loudspeaker with a powered subwoofer, such as the Vandersteen Quatro Wood); if you don't, it's easily defeated with a direct-input bypass.

The Atlas's front panel features a largish LED display (for a power amplifier), and five contact switches, which control power, illumination, and the high-pass crossover-frequency submenu. The rear panel accommodates single-ended and balanced inputs. The binding posts are the single-knobbed Cardas design. There are also RS-232 and remote trigger inputs, as well as a fused AEC mains plug.

Atlas unmoved
Setup was a breeze. There are no switches with which to choose single-ended or balanced operation, so the Atlas is plug'n'playunless you want to use the high-pass filter, which requires accessing the submenu. None of the speakers I had on hand required the filter, so that wasn't an issue.

The Atlas is heavy and benefits from good ventilation, so proper support and placement are required. The amp doesn't get hot so much as quite warmish. Also, while the Atlas has five rubber feet, which damp the underside of its chassis fairly well, I discovered that it benefited from aftermarket footersI cycled through brass cones, DH Labs ceramic cones, and ultimately settled on Ayre's blocks of myrtle wood. If you feel an $8000 amp shouldn't require aftermarket mods, you're welcome to skip them, but I found the Ayres added a touch more, um, air (or, alternatively, eliminated a slight amount of chassis ringing). I also scattered a few myrtle blocks on the amp's top plate, a conceit that amused my cats, who would sweep them off before settling down for a heated nap. (Cats, too, do a good job of damping the top plate, but they're unreliable suckers.)

I listened to the Atlas driving three different pairs of speakers: Klipsch's F-39 Palladium, Thiel's CS3.7, and Vienna Acoustics' Klimt The Kiss. Nonenot even the Thielsseemed to challenge the Atlas's rock-solid control.

Heavenly Music
Control, ease, and dynamic command were the first properties I noticed about the Atlas. It took charge of a pair of loudspeakers and made 'em behave.

From the Tin Hat Trio's Memory Is an Elephant (CD, Angel 56786), "The Would-Be Czarina" had a timbral correctness that made the trio's subdued dynamic range really pop. Released on Angel, ostensibly a classical label, the THT's version of chamber music has haunting undertones. This track begins with Mark Ortron's jangly guitar juxtaposed over sustained chords from Carla Kilstedt's viola. The Atlas gave the duo a vividness that belied their pianissimo level. Later, the two instruments exchange places, leaving Rob Berger's asthmatic organ chords to handle the fundamental. "The Would-Be Czarina" seems simple, but it's notthrough the Atlas, it was vivid and engrossing.